1. Field of the Invention
The present invention relates to a versatile, latency-independent interface between hardware components, such as between a read/write (R/W) channel or read channel (RDC) and a hard disk controller (HDC). Such an interface is flexible enough to support high read and write latencies of greater than one sector, a split sector format, and a second sector mark.
2. Description of the Related Art
As is shown in FIG. 1, a typical disk drive system includes a hard disk controller (HDC) 12 that interfaces with a R/W channel or RDC 14 which is in communication with a disk 16. Data transfer between HDC 12 and the R/W channel is synchronized by read gate (RGATE) and write gate (WGATE) control signals. In a read operation, R/W channel 14 processes an incoming analog signal from disk 16 and transfers the data to HDC 12. In a write operation, data is transferred from HDC 12 to the R/W channel to be written to the disk. Latency refers to the time or byte delay that data remains in the R/W channel. Some disk drive systems have latencies of about 20 bytes which, depending on the particular system, amounts to a time delay of between about 800 ns and 5 ms.
Technology such as iterative turbo coding, which is being introduced into modern disk drive systems, requires more processing before the data is available, which, in turn, requires R/W channels or RDCs with higher latencies. One problem is that the interface used in the shorter latency systems is not capable of supporting the higher latencies. Accordingly, a new interface is needed that supports higher latency R/W channel or RDC designs.